Damage to the olfactory nerves is thought to result in anosmia (loss of olfactory function) by preventing signals from odor receptor cells from reaching the brain. At the present time little hope is offered to those with impaired olfactory function. This project will combine molecular techniques with a nerve regeneration model to investigate the capacity of olfactory neurons to regenerate, replace, and repair damaged neurons in the central nervous system. Genetic markers introduced into a strain of transgenic mice will be used to trace regenerating olfactory nerves as they grow back to their target sites in the olfactory bulb. Experiments will determine if the regenerating nerve fibers can restore sensory maps in olfactory brain regions. Age related changes in sensory maps will also be investigated. Immunocytochemical methods will be used to determine the time course and location of new synapse formation during recovery from nerve transection. Behavioral experiments will determine the amount of reconnection needed to restore odor mediated behavior and if increasing odor exposure (odor therapy) helps to improve the time course of recovery. Results from this study could have important clinical implications for rehabilitation and recovery of function following brain injury. Findings could provide the foundation for future treatment strategies to help improve or restore function in individuals with anosmia and other brain related injuries.